Mechanical Properties Analysis Of Column Base Joint Of Adding Story With Light Weight Steels On The Top Of Concrete Frame Structure

In recent years, structures added with light weight steels have been widespread in theold building reconstruction project. As a connection hub of the original structure andadded layer structure, column base joint is the key to ensure successful adding storiesstructures. At present, related standard and specifications are not come out as thedesign basis. So it is particularly important to study the column base joint of addingstories with the light steel.The seismic performance of adding stories determines the seismic performance of thewhole structure after adding stories. The seismic performance of traditional column basejoint is comparatively bad. In the project of adding stories with the light steel, a newcolumn base joint with good seismic performance is proposed by taking example ofsemi-embeded column base. A concrete column cap satisfying the enlargedcross-section of steel column installation requirements is cast to some height on the topcolumn of original structure. Then the steel column is installed on it and reinforcedconcrete cover is cast at the bottom of the steel column.In this paper, numeric models have been created with finite element analyticsoft-ABAQUS to study the seismic performance of the new column base joint.At thesame time, the column base joint that steel column connects on the concrete columndirectly have been created to compare with the new column base joint. The analysis oncracks, deformation, stress distribution, hysteretic loops, envelope curves have beencarried out for further study of the confinement mechanism of column base joints ofappending story with light weight steel. Simultaneously this paper analyses the primaryfactor affecting structural behavior by changing joints’parameter．The results have certain reference value to the light steel adding stories structuraldesign, which can be used as references for similar projects．...